the objective is to determine experimentally in a sub-human primate the most effective scheme of administration of antineoplastic agents to attain the most efficient and effective disposition of antineoplastic drugs in cerebrospinal fluid and brain per se and to determine similar parameters in the presence of experimentally induced brain tumors. To this end has been devised an animal (monkey) model that permits the determination of the kinetics of distribution of antineoplastic drugs in CSF (lumber, cisterna magna, supracerebrocortical and lateral ventricular) together with concommittant determination of the kinetic profile of drugs in blood and brain when the drug is initially instilled into the vascular or CSF pathways. This experimental design permits the direct determination of those chemotherapeutic parameters necessary to treat a specific (drug sensitive) induced brain tumor and examine conditions which promote or inhibit the deposition of antitumoral agents in brain per se and tumor bearing brain.